Reformed coal production equipment, and method for controlling same

ABSTRACT

Reformed coal production equipment includes: a combustion furnace ( 124 ) generating heated gas; dry distillation gas supply pipe ( 101 ) supplying dry distillation gas ( 14 ) generated at the inner cylinder ( 122 ) of a dry distillation device ( 121 ) to the combustion furnace; vapor generator ( 125 ) to which a portion of the heated gas ( 11 ) generated at the combustion furnace is supplied and which generates waste heat gas ( 13 ) by subjecting the heated gas to heat exchange; and discharge pipe ( 52 ), waste heat gas delivery pipe ( 53 ), mixed gas delivery pipe ( 55 ), blower ( 126 ), mixed gas supply pipe ( 56 ), mixed gas branching pipe ( 102 ), flow rate adjustment valve ( 103 ), and mixed gas allocation pipe ( 105 ) which supply and allocate, to the aforementioned inner cylinder, the waste heat gas and low-temperature heated gas ( 12 ) generated by indirectly heating dried coal ( 2 ) by the heated gas within the outer cylinder ( 123 ) of the dry distillation device.

TECHNICAL FIELD

The present invention relates to upgraded coal production equipment and a method for controlling the same, and is particularly useful when used to upgrade coal of low rank (low-rank coal), such as brown coal or subbituminous coal, which is porous and has a high water content.

BACKGROUND ART

Coal of low rank (low-rank coal), such as brown coal or subbituminous coal, which is porous and has a high water content generates a low amount of heat per unit weight, and is therefore dried through a heating treatment to have improved amount of heat generation per unit weight.

As upgraded coal production equipment configured to perform such upgrade of low-rank coal, there is, for example, equipment including: an indirect-heating pyrolysis device which performs pyrolysis on low-rank coal by heating the low-rank coal indirectly by use of a heating gas; and a combustion furnace which generates the heating gas by combusting a pyrolysis gas generated in the pyrolysis device and supplied to the combustion furnace through a pyrolysis gas supply pipe.

The pyrolysis gas described above is composed of a low-boiling component. However, since the low-rank coal is processed under a relatively high temperature, the pyrolysis gas is accompanied by tar (pyrolysis oil) which is a high-boiling component. When the pyrolysis gas is cooled, the tar is attached to a wall surface of a duct or the like through which the pyrolysis gas flows. When a large amount of tar is attached, a problem might occur, such as clogging the duct. Hence, various techniques have been developed to remove the tar.

For example, Patent Document 1 given below discloses a decoking method for combusting and removing coke attached to the inside of a pipe by use of a gas which is obtained by adjusting air to have an oxygen concentration of 3 vol % to 21 vol % through dilution with water vapor or an inert gas, and which is also adjusted to have a temperature of 350° C. to 500° C.

Patent Document 2 given below discloses a method for performing a pyrolysis treatment on a processed object by using an external heating kiln. In this method, an oxygen-containing gas is supplied into an inner cylinder of the external heating kiln to combust a carbide of organic matter in the processed object and/or a combustible gas, which are produced by pyrolysis. Thereby, the temperature of a pyrolysis gas increases, so that liquefaction or solidification is prevented.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Patent Application Publication No. Hei 5-188653 (see, e.g., paragraphs [0013], [0017], and the like) Patent Document 2: Japanese Patent Application Publication No. 2004-3738 (see, e.g., paragraphs [0011], [0014], [0015], and the like)

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

By applying the decoking method described in Patent Document 1 to the upgraded coal production equipment described earlier to directly supply the oxygen-concentration adjusted gas adjusted for its oxygen concentration to the pyrolysis device described earlier, tar produced during shutdown is combusted, so that attachment of the tar to the pyrolysis device can be suppressed. However, generating the oxygen-concentration adjusted gas from air or from an inert gas (nitrogen or water vapor) requires an apparatus specialized for that, and this increases costs for producing upgraded coal. Moreover, the oxygen-concentration adjusted gas has to be increased in temperature in advance in order for it to react with the tar. Thus, additional energy is needed. In sum, the tar cannot be removed efficiently.

In the method for performing a pyrolysis treatment on a processed object by using an external heating kiln described in Patent Document 2, the carbide itself of organic matter in the processed object produced by the pyrolysis is combusted. Thus, when this method is applied to the upgraded coal production equipment, coal has to be supplied to the pyrolysis device also during shutdown of the equipment to combust the coal itself. This entails lower production volume of the upgraded coal.

In view of the above, the present invention has been made to solve the problems described above, and has an objective of providing upgraded coal production equipment and a controlling method for the same, capable of efficient tar removal without lowering the production volume of upgraded coal even in shutting down the equipment.

Means for Solving the Problems

Upgraded coal production equipment according to a first aspect of the invention for solving the above problems is upgraded coal production equipment which includes drying means for drying coal, pyrolysis means for performing pyrolysis on the dried coal, and cooling means for cooling the coal subjected to the pyrolysis, the pyrolysis means being an indirect-heating pyrolysis device having an inner cylinder into which the dried coal is transferred and an outer cylinder supplied with a heating gas for heating the inner cylinder, and which is characterized in that the equipment comprises: heating gas generation means for generating the heating gas; pyrolysis gas supply means for supplying the heating gas generation means with a pyrolysis gas generated in the inner cylinder; waste-heat gas generation means for receiving supply of part of the heating gas generated in the heating gas generation means and generating a waste-heat gas by subjecting the heating gas to heat exchange; and mixed gas distribution supply means for distributing and supplying, to the inner cylinder, the waste-heat gas and a low-temperature heating gas generated when the heating gas heats the coal indirectly inside the outer cylinder.

Upgraded coal production equipment according to a second aspect of the invention for solving the above problems is the upgraded coal production equipment according to the first aspect of the invention described above, characterized in that the mixed gas distribution supply means is connected to the inner cylinder at an inlet side of the inner cylinder which receives the dried coal.

Upgraded coal production equipment according to a third aspect of the invention for solving the above problems is the upgraded coal production equipment according to the second aspect of the invention described above, characterized in that the indirect-heating pyrolysis device includes gas temperature measurement means for measuring a gas temperature, the gas temperature measurement means being provided at an outlet side from which the dried coal is discharged, and the mixed gas distribution supply means includes: gas flow rate adjustment means for adjusting a flow rate of the low-temperature heating gas and the waste-heat gas supplied to the inner cylinder; and control means for controlling the gas flow rate adjustment means based on the gas temperature measured by the gas temperature measurement means.

Upgraded coal production equipment according to a fourth aspect of the invention for solving the above problems is the upgraded coal production equipment according to the third aspect of the invention described above, characterized in that the equipment comprises a plurality of equipment main bodies being arranged in parallel and each having the drying means, the indirect-heating pyrolysis device, and the cooling means.

A method for controlling upgraded coal production equipment according to a fifth aspect of the invention for solving the above problems is a method for controlling the upgraded coal production equipment according to the third aspect of the invention described above, characterized in that the method comprises: stopping supply of the coal to the inner cylinder; supplying the low-temperature heating gas and the waste-heat gas to the inner cylinder through control of the gas flow rate adjustment means by the control means, and meanwhile increasing an amount of fuel supplied to the heating gas generation means; and stopping the supply of the low-temperature heating gas and the waste-heat gas to the inner cylinder through control of the gas flow rate adjustment means by the control means when the gas temperature measured by the gas temperature measurement means falls below a predetermined temperature.

A method for controlling upgraded coal production equipment according to a sixth aspect of the invention for solving the above problems is a method for controlling the upgraded coal production equipment according to the fourth aspect of the invention described above, characterized in that the method comprises: in the equipment main body to be shut down, stopping supply of the coal to the inner cylinder, and meanwhile, in the equipment main body in steady operation, increasing an amount of the coal supplied to the drying means and increasing an amount of the heating gas supplied to the outer cylinder; in the equipment main body to be shut down, starting supply of the low-temperature heating gas and the waste-heat gas to the inner cylinder through control of the gas flow rate adjustment means by the control means; in the equipment main body to be shut down, stopping the supply of the heating gas to the inner cylinder when all the coal is discharged from the inner cylinder, and meanwhile, in the equipment main body in steady operation, bringing the supply of the heating gas to the outer cylinder to a steady state; and in the equipment main body to be shut down, stopping the supply of the low-temperature heating gas and the waste-heat gas to the inner cylinder through control of the gas flow rate adjustment means by the control means when all the pyrolysis gas is discharged from the inner cylinder.

Effect of the Invention

According to the present invention, when the equipment is to be shut down, the heating gas can be supplied to the indirect-heating pyrolysis means until the coal (pyrolysis coal) is discharged from the indirect-heating pyrolysis means, so as to prevent tar from being newly generated by cooling of the coal. By the supply of the low-temperature heating gas and the waste-heat gas to the indirect-heating pyrolysis means, the indirect-heating pyrolysis means and the pyrolysis gas supply means can be purged of the pyrolysis gas. Hence, tar can be prevented from being attached to the inner wall surfaces of the indirect-heating pyrolysis means and of the pyrolysis gas supply means. Moreover, the oxygen concentration of each of the low-temperature heating gas and the waste-heat gas is about 2 to 3%. Thus, even if tar is attached to the inner wall surfaces of the indirect-heating pyrolysis means and the pyrolysis gas supply means, the tar can be combusted and removed. Hence, even in shutting down the equipment, efficient tar removal can be achieved without lowering the production volume of the upgraded coal. Since the indirect-heating pyrolysis means, the pyrolysis gas supply means, and the like do not need tar removal work, maintenance and inspection work can be performed efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing the overall configuration of upgraded coal production equipment according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a control flow performed by the upgraded coal production equipment according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram showing the overall configuration of upgraded coal production equipment according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a control flow performed by the upgraded coal production equipment according to the second embodiment of the present invention.

MODE FOR CARRYING OUT THE INVENTION

Upgraded coal production equipment and a method for controlling the upgraded coal production equipment according to the present invention are described using embodiments.

Embodiment 1

Based on FIGS. 1 and 2, a description is given of upgraded coal production equipment according to a first embodiment of the present invention.

In upgraded coal production equipment 100 according to this embodiment, first, as shown in FIG. 1, low-rank coal 1 such as brown coal or subbituminous coal is supplied to a drying device 111 by a hopper or the like (not shown), the drying device 111 being drying means for drying the low-rank coal 1. An outlet of the drying device 111 communicates with an inlet 122 a of a pyrolysis device 121 configured to perform pyrolysis on dried coal 2. An outlet 122 b of the pyrolysis device 121 communicates with an inlet of a cooling device 131 being cooling means for cooling pyrolysis coal 3.

The pyrolysis device 121 has an inner cylinder 122 and an outer cylinder 123 surrounding the inner cylinder 122. The outer cylinder 123 is supplied with a heating gas 11 to be described later. Thereby, the dried coal 2 supplied into the inner cylinder 122 is indirectly heated and is subjected to pyrolysis, to generate the pyrolysis coal 3. In other words, the pyrolysis device 121 is an indirect-heating device, such as, e.g., an external heating kiln, in which a hot gas (heating gas) being a heat source does not come into direct contact with the low-rank coal 1. The pyrolysis device 121 forms indirect-heating pyrolysis means.

A gas exhaust port of the inner cylinder 122 of the pyrolysis device 121 communicates with a gas intake port of a combustion furnace 124 via a pyrolysis gas supply pipe 101. Thereby, a pyrolysis gas 14 containing gaseous tar (pyrolysis oil) generated by the pyrolysis is supplied to the gas intake port of the combustion furnace 124. The gas intake port of the combustion furnace 124 is also supplied with a fuel (not shown) such as a natural gas. The combustion furnace 124 generates the heating gas 11 by combusting the pyrolysis gas 14 and the fuel such as a natural gas. In other words, the combustion furnace 124 forms heating gas generation means. A gas exhaust port of the combustion furnace 124 communicates with a gas intake port of the outer cylinder 123 of the pyrolysis device 121 via a heating gas feed pipe 51.

The heating gas feed pipe 51 communicates with a gas intake port of a steam generator 125 via a heating gas branch pipe 53. The steam generator 125 forms waste-heat gas generation means for generating a waste-heat gas 13 through heat exchange between the heating gas 11 and water to thereby generate water vapor. A gas exhaust port of the steam generator 125 communicates with an exhaust pipe 52 to be described later via a waste-heat gas feed pipe 54.

A gas exhaust port of the outer cylinder 123 of the pyrolysis device 121 communicates with a gas intake port of an exhaust-gas treatment device 127 via the exhaust pipe 52, the exhaust-gas treatment device 127 being exhaust-gas purification means for purifying the waste-heat gas 13 and a low-temperature heating gas 12 which is generated when the heating gas 11 heats the inner cylinder 122. The low-temperature heating gas 12 and the waste-heat gas 13 are discharged to the outside of the system after undergoing the purification treatment in the exhaust-gas treatment device 127.

The exhaust pipe 52 communicates with a gas intake port of a blower 126 via a mixed gas feed pipe 55. A gas exhaust port of the blower 126 communicates with a gas intake port of the combustion furnace 124 via a mixed gas supply pipe 56. The mixed gas supply pipe 56 communicates with a mixed gas branch pipe 102. The mixed gas branch pipe 102 communicates with a mixed gas communication pipe 104 via a flow rate adjustment valve (three-way valve) 103, and also communicates with a mixed gas distribution pipe 105 via the flow rate adjustment valve 103. The mixed gas communication pipe 104 communicates with the pyrolysis gas supply pipe 101. The mixed gas distribution pipe 105 communicates with a gas intake port of the inlet 122 a side of the inner cylinder 122 of the pyrolysis device 121.

The pyrolysis gas supply pipe 101 is provided with a gas temperature measurement instrument 106 which is gas temperature measurement means for measuring the temperature of a gas inside the pipe. The gas temperature measurement instrument 106 is connected to a control device 109 such that the measured gas temperature can be sent to the control device 109. The pyrolysis gas supply pipe 101 is provided with differential-pressure measurement instruments 107 a, 107 b configured to measure the differential pressure inside the pipe. The differential-pressure measurement instruments 107 a, 107 b are connected to the control device 109 such that the measured differential pressure inside the pipe can be sent to the control device 109.

The outlet 122 b of the inner cylinder 122 of the pyrolysis device 121 is provided with an inner-cylinder gas temperature measurement instrument 108 which is gas temperature measurement means for measuring the temperature of a gas inside the inner cylinder 122. The inner-cylinder gas temperature measurement instrument 108 is connected to the control device 109 such that the measured gas temperature inside the inner cylinder can be sent to the control device 109.

The exhaust pipe 52, the waste-heat gas feed pipe 54, the mixed gas feed pipe 55, the blower 126, the mixed gas supply pipe 56, the mixed gas branch pipe 102, the flow rate adjustment valve 103, the mixed gas distribution pipe 105, and the like form mixed gas distribution supply means. The flow rate adjustment valve 103 forms gas flow rate adjustment means for adjusting the amount of the low-temperature heating gas 12 and the waste-heat gas 13 supplied to the pyrolysis device 121.

Based on the measurement values obtained by the various measurement instruments, the control device 109 controls the flow rate adjustment valve 103, the amount of fuel supplied to the combustion furnace 124, the amount of the low-rank coal 1 supplied to the drying device 111, the amount of the heating gas 11 supplied to the pyrolysis device 121, and the like. In other words, the control device 109 forms control means for adjusting the valve position of the flow rate adjustment valve 103 and the like based on the measurement values obtained by the various measurement instruments.

In the upgraded coal production equipment 100 according to this embodiment thus configured, when the low-rank coal 1 is charged into the hopper, the hopper supplies the low-rank coal 1 at a room temperature to the drying device 111 a predetermined amount at a time. The low-rank coal 1 supplied to the drying device 111 is removed of water and becomes the dried coal 2 by being heated up to about 200° C. by a drying combustion gas (about 150 to 300° C.) from a drying combustor (not shown). Then, the dried coal 2 is transferred into the inner cylinder 122 of the pyrolysis device 121. The dried coal 2 transferred to the pyrolysis device 121 is subjected to pyrolysis by being indirectly heated by the heating gas 11 (gas temperature: about 1050° C., oxygen concentration: about 2 to 3%) from the combustion furnace 124. Thereby, the dried coal 2 becomes the pyrolysis coal 3 as a result of removal of components such as the pyrolysis gas 14 containing gaseous tar, and the pyrolysis coal 3 is fed to the cooling device 131. The pyrolysis coal 3 fed to the cooling device 131 becomes upgraded coal 4 by being cooled down to about 50° C.

Meanwhile, the heating gas 11 (gas temperature: about 1050° C., oxygen concentration: about 2 to 3%) generated in the combustion furnace 124 is fed to the outer cylinder 123 of the pyrolysis device 121 via the heating gas feed pipe 51. The heating gas 11 used inside the outer cylinder 123 to heat the inner cylinder 122 becomes the low-temperature heating gas 12 (gas temperature: about 350° C., oxygen concentration: about 2 to 3%). The low-temperature heating gas 12 is fed to the exhaust pipe 52. Meanwhile, the heating gas 11 is also fed to the steam generator 125 via the heating gas feed pipe 51 and the heating gas branch pipe 53. The heating gas 11 used in the steam generator 125 for generation of water vapor becomes the waste-heat gas 13 (gas temperature: about 350° C., oxygen concentration: about 2 to 3%). The waste-heat gas 13 is fed to the exhaust pipe 52 via the waste-heat gas feed pipe 54.

Part of the low-temperature heating gas 12 and the waste-heat gas 13 is supplied to the exhaust-gas treatment device 127. The low-temperature heating gas 12 and the waste-heat gas 13 undergo the purification treatment in the exhaust-gas treatment device 127 and are then discharged to the outside of the system. The rest of the low-temperature heating gas 12 and the waste-heat gas 13 (gas temperature: about 350° C., oxygen concentration: about 2 to 3%) is fed to the blower 126 via the mixed gas feed pipe 55.

Part of the low-temperature heating gas 12 and the waste-heat gas 13 fed to the blower 126 is supplied to the combustion furnace 124 via the mixed gas supply pipe 56. The rest of the low-temperature heating gas 12 and the waste-heat gas 13 (gas temperature: about 350° C., oxygen concentration: about 2 to 3%) fed to the blower 126 is supplied to the mixed gas branch pipe 102. The rest of the low-temperature heating gas 12 and the waste-heat gas 13 (gas temperature: about 350° C., oxygen concentration: about 2 to 3%) supplied to the mixed gas branch pipe 102 is supplied to the pyrolysis gas supply pipe 101 via the flow rate adjustment valve 103 and the mixed gas communication pipe 104, or supplied to the inlet 122 a side of the inner cylinder 122 of the pyrolysis device 121 via the flow rate adjustment valve 103 and the mixed gas distribution pipe 105.

The valve position of the flow rate adjustment valve 103 is controlled by the control device 109 based on the gas temperature measured by the gas temperature measurement instrument 106. For example, the control device 109 adjusts the flow rate adjustment valve 103 by opening it to increase the aperture when the gas temperature measured by the gas temperature measurement instrument 106 is equal to or higher than 400° C., and adjusts the flow rate adjustment valve 103 by narrowing it when the gas temperature exceeds 550° C. Thereby, the low-temperature heating gas 12 and the waste-heat gas 13 (oxygen concentration: about 2 to 3%) are mixed with the pyrolysis gas 14 (gas temperature: about 400° C., oxygen concentration: about 0%), and this mixed gas has an oxygen concentration adjusted to about 1 to 2%. As a result, gaseous tar (pyrolysis oil) is oxidatively decomposed (decoking) to become light in weight, and thereby attachment of the tar to the pyrolysis gas supply pipe 101 can be prevented. The tar is reduced in weight to become a light gas, and this light gas is combusted. Thus, decrease in the gas temperature is prevented. Thereby, attachment of the tar to the pyrolysis gas supply pipe 101 can be prevented. Specifically, the decoking is performed just when the tar is about to be attached to the inner wall surface of the pyrolysis gas supply pipe 101 by adjustment of the amount of the low-temperature heating gas 12 and the waste-heat gas 13 supplied to the pyrolysis gas supply pipe 101 based on the gas temperature inside the pyrolysis gas supply pipe 101. Hence, the tar can be efficiently removed.

With reference to FIG. 2, a description is given of operation performed when shutting down the upgraded coal production equipment 100 according to this embodiment configured as above.

As shown in FIG. 2, first, the upgraded coal production equipment 100 is in steady operation (Step SA1). To shut down this upgraded coal production equipment 100, transfer of the dried coal 2 to the inner cylinder 122 of the pyrolysis device 121 is stopped (Step SA2).

Next, the flow proceeds to Step SA3 as well as to Step SA11. In Step SA11, since the dried coal 2 is not newly transferred to the inner cylinder 122 of the pyrolysis device 121, the amount of the pyrolysis gas 14 generated decreases. The decrease in the generated amount of the pyrolysis gas 14 results in a decreased amount of the pyrolysis gas 14 supplied to the combustion furnace 124. However, by increasing the amount of fuel, such as a natural gas, supplied to the combustion furnace 124 to increase the amount of additional gas to be supplied to the combustion furnace 124, decrease in the gas temperature and generated amount of the heating gas 11 can be suppressed. In sum, the amount of additional gas to be supplied to the combustion furnace is increased (Step SA12). Thereafter, all the pyrolysis coal 3 is discharged from the pyrolysis device 121 (Step SA13). This means that the pyrolysis device 121 generates no more pyrolysis gas 14.

Meanwhile, in Step SA3, the control device 109 adjusts the flow rate adjustment valve 103 to start supply of the low-temperature heating gas 12 and the waste-heat gas 13 to the inlet 122 a side of the inner cylinder 122 of the pyrolysis device 121 via the mixed gas distribution pipe 105. In other words, the low-temperature heating gas 12 and the waste-heat gas 13 are forcibly supplied into the inner cylinder 122 of the pyrolysis device 121 from the inlet 122 a side thereof. Thereby, the inner cylinder 122 of the pyrolysis device 121 and the pyrolysis gas supply pipe 101 are purged of the pyrolysis gas 14.

Subsequently, since all the pyrolysis coal 3 is discharged from the inside of the inner cylinder 122 of the pyrolysis device 121, no pyrolysis gas 14 is generated by the indirect heating of the dried coal 2. As a result, no pyrolysis gas 14 is supplied to the combustion furnace 124. Thus, the amount of additional gas to be supplied to the combustion furnace 124 is decreased (Step SA4). This consequently decreases the gas temperature and generated amount of the heating gas 11 generated in the combustion furnace 124 (Step SA5).

Next, since the heating gas 11 which is less in amount and lower in temperature than in the steady operation is supplied to the outer cylinder 123 of the pyrolysis device 121, the temperature of the pyrolysis device 121 decreases (Step SA6). This consequently decreases the temperature of the low-temperature heating gas 12 itself and also the temperature of the waste-heat gas 13 (Step SA7).

Then, the flow proceeds to Step SA8 in which the control device 109 makes a judgment based on the gas temperature inside the inner cylinder measured by the inner-cylinder gas temperature measurement instrument 108. When the gas temperature near the outlet 122 b of the inner cylinder 122 of the pyrolysis device 121 is higher than 300° C., the flow returns to Step SA4. On the other hand, when the gas temperature near the outlet 122 b of the inner cylinder 122 of the pyrolysis device 121 is equal to or lower than 300° C., the flow proceeds to Step SA9 in which the control device 109 controls the flow rate adjustment valve 103 to close the flow rate adjustment valve 103. In other words, supply of the low-temperature heating gas 12 and the waste-heat gas 13 to the inner cylinder 122 of the pyrolysis device 121 is stopped.

Hence, in the upgraded coal production equipment 100 according to this embodiment, in shutting down the equipment, the low-temperature heating gas 12 and the waste-heat gas 13 are supplied to the inlet 122 a side of the inner cylinder 122 of the pyrolysis device 121 to forcibly discharge the pyrolysis gas 14 inside the inner cylinder 122 of the pyrolysis device 121 and inside the pyrolysis gas supply pipe 101. Moreover, this pyrolysis gas 14 is combusted in the combustion furnace 124.

Further, since the oxygen concentration of the low-temperature heating gas 12 and the waste-heat gas 13 is about 2 to 3%, tar can be oxidatively decomposed to become light in weight. The gas thus reduced in weight flows the combustion furnace 124 and combusted inside the combustion furnace 124. Even if tar is attached to the inner wall surface of the inner cylinder 122 of the pyrolysis device 121 or the inner wall surface of the pyrolysis gas supply pipe 101, the tar can be removed by combustion.

Thus, even in shutting down the equipment, tar can be efficiently removed without lowering the production volume of the upgraded coal 4. In addition, since tar can be prevented from being attached to the inner wall surfaces of the inner cylinder 122 of the pyrolysis device 121 and the pyrolysis gas supply pipe 101, maintenance and inspection work can be efficiently performed.

Embodiment 2

Based on FIGS. 3, 4A, and 4B, upgraded coal production equipment according to a second embodiment of the present invention is described.

As shown in FIG. 3, the upgraded coal production equipment according to this embodiment includes three upgraded coal production equipment main bodies 100A, 100B, and 100C arranged in parallel. Like the upgraded coal production equipment 100 according to the first embodiment described above, the upgraded coal production equipment main bodies 100A, 100B, and 100C each include a drying device 111, a pyrolysis device 121, and a cooling device 131.

Like the upgraded coal production equipment 100 according to the first embodiment described above, the upgraded coal production equipment according to this embodiment includes one combustion furnace 124, one blower 126, and one exhaust-gas treatment device 127. A gas exhaust port of the blower 126 communicates with a gas intake port of the combustion furnace 124 via a mixed gas supply pipe 56. A gas exhaust port of the combustion furnace 124 communicates with an outer cylinder 123 of a pyrolysis device 121 of each of the equipment main bodies 100A, 100B, and 100C via a corresponding one of heating gas feed pipes 51 a to 51 c.

The heating gas feed pipes 51 a to 51 c communicate with gas intake ports of steam generators 125 via heating gas branch pipes 53 a to 53 c, respectively. Gas exhaust ports of the steam generators 125 communicate with waste-heat gas feed pipes 54 a to 54 c, respectively.

Gas exhaust ports of the outer cylinders 123 of the pyrolysis devices 121 communicate with exhaust pipes 52 a to 52 c, respectively. Part of a waste-heat gas 13 and a low-temperature heating gas 12 which is generated when a heating gas 11 heats inner cylinders 122 is supplied via waste-heat gas feed pipe 54 a to 54 c or the exhaust pipes 52 a to 52 c to the exhaust-gas treatment device 127 being exhaust gas purification means for performing purification treatment on the low-temperature heating gas 12 and the waste-heat gas 13, and is discharged to the outside of the system after undergoing the purification treatment in the exhaust-gas treatment device 127. The rest of the low-temperature heating gas 12 and the waste-heat gas 13 is supplied to the blower 126 via the exhaust pipes 52 a to 52 c or the waste-heat gas feed pipes 54 a to 54 c and the mixed gas feed pipe 55.

Gas exhaust ports of the inner cylinders 122 of the pyrolysis devices 121 communicate with gas intake ports of the combustion furnace 124 via pyrolysis gas supply pipes 101 a to 101 c, respectively.

The mixed gas supply pipe 56 communicates with mixed gas branch pipes 102 a to 102 c. The mixed gas branch pipes 102 a to 102 c communicate with mixed gas communication pipes 104 a to 104 c via flow rate adjustment valves (three-way valves) 103 a to 103 c, respectively, and also communicate with mixed gas distribution pipes 105 a to 105 c via the flow rate adjustment valves 103 a to 103 c, respectively. The mixed gas communication pipes 104 a to 104 c communicate with the pyrolysis gas supply pipes 101 a to 101 c, respectively. The mixed gas distribution pipes 105 a to 105 c communicate with gas intake ports of the inlet 122 a side of the inner cylinders 122 of the pyrolysis devices 121, respectively.

The pyrolysis gas supply pipe 101 a is provided with a gas temperature measurement instrument 106 being gas temperature measurement means for measuring the gas temperature inside the pipe. The gas temperature measurement instrument 106 is connected to the control device 109 such that the measured gas temperature can be sent to the control device 109. Like the pyrolysis gas supply pipe 101 a, the pyrolysis gas supply pipes 101 b and 101 c are each provided with a gas temperature measurement instrument (not shown), as well. These gas temperature measurement instruments are also connected to the control device 109 such that the gas temperature measured by the gas temperature measurement instruments can be sent to the control device 109.

The pyrolysis gas supply pipe 101 a is provided with the differential-pressure measurement instruments 107 a, 107 b configured to measure the differential pressure in the pipe. The differential-pressure measurement instruments 107 a, 107 b are connected to the control device 109 such that the measured differential pressure in the pipe can be sent to the control device 109. Like the pyrolysis gas supply pipe 101 a, the pyrolysis gas supply pipes 101 b and 101 c are each provided with differential-pressure measurement instruments (not shown), as well. These differential-pressure measurement instruments are also connected to the control device 109 such that the differential pressure in the pipe measured by the differential-pressure measurement instruments can be sent to the control device 109.

The outlet 122 b of the inner cylinder 122 of the pyrolysis device 121 of the equipment main body 100A is provided with an inner-cylinder gas temperature measurement instrument 108 configured to measure the temperature of the gas inside the inner cylinder 122. The inner-cylinder gas temperature measurement instrument 108 is connected to the control device 109 such that the measured temperature of the gas inside the inner cylinder can be sent to the control device 109. Like the equipment main body 100A, the outlet 122 b of the inner cylinder 122 of the pyrolysis device 121 of each of the equipment main bodies 100B and 100C is also provided with an inner-cylinder gas temperature measurement instrument (not shown) configured to measure the temperature of the gas inside the inner cylinder 122. These inner-cylinder gas temperature measurement instruments are also connected to the control device 109 such that the measured temperature of gas inside the inner cylinder can be sent to the control device 109.

The exhaust pipes 52 a to 52 c, the waste-heat gas feed pipes 54 a to 54 c, the mixed gas feed pipe 55, the blower 126, the mixed gas supply pipe 56, the mixed gas branch pipes 102 a to 102 c, the flow rate adjustment valves 103 a to 103 c, the mixed gas distribution pipes 105 a to 105 c, and the like form mixed gas distribution supply means. The flow rate adjustment valves 103 a to 103 c form gas flow rate adjustment means for adjusting the amount of the low-temperature heating gas 12 and the waste-heat gas 13 supplied to the pyrolysis devices 121 of the equipment main bodies 100A, 100B, and 100C, respectively.

Based on the measurement values of the various measurement instruments, the control device 109 controls the flow rate adjustment valves 103 a to 103 c, the amount of fuel supplied to the combustion furnace 124, the amount of the low-rank coal 1 supplied to the drying device 111 of each of the equipment main bodies 100A, 100B, and 100C, the amount of the heating gas 11 supplied to the pyrolysis device 121 of each of the equipment main bodies 100A, 100B, and 100C, and the like. In other words, the control device 109 forms control means for adjusting the valve positions of the flow rate adjustment valves 103 a to 103 c and the like based on the measurement values obtained by the various measurement instruments.

In the upgraded coal production equipment according to this embodiment thus configured, the operation for performing control to prevent attachment of tar to the pyrolysis gas supply pipes 101 a, 101 b, and 101 c during the steady operation is the same as that performed by the upgraded coal production equipment 100 according to the first embodiment described above, and is therefore not described again here.

With reference to FIGS. 4A and 4B, operation performed when a upgraded coal production equipment main body of the upgraded coal production equipment according to this embodiment is shut down and then returns to a steady operation state.

In a case described, while the upgraded coal production equipment main bodies 100E and 100C are in a steady operation state, the upgraded coal production equipment main body 100A is shut down and then returns to the steady operation state.

As shown in FIGS. 4A and 4B, first, the upgraded coal production equipment main body 100A is in steady operation (Step SB1). The upgraded coal production equipment main bodies 100B and 100C are also in steady operation (Step SC1).

To shut down the upgraded coal production equipment main body 100A, transfer of the dried coal 2 to the inner cylinder 122 of the pyrolysis device 121 is stopped (Step SB2). Since this decreases the amount of the dried coal 2 inside the inner cylinder 122 of the pyrolysis device 121 of the equipment main body 100A, the amount of the heating gas 11 supplied from the combustion furnace 124 to the outer cylinder 123 of the pyrolysis device 121 is decreased (Step SB3). Thus, thermal load in the pyrolysis device 121 of the equipment main body 100A decreases. Meanwhile, in the equipment main bodies 100B and 100C, the amount of the dried coal 2 transferred to the inner cylinder 122 of the pyrolysis device 121 of each of the equipment main bodies 100E and 100C is increased (Step SC2). Since this increases the amount of the dried coal 2 inside the inner cylinder 122 of the pyrolysis device 121 of each of the equipment main bodies 100E and 100C, the amount of the heating gas 11 supplied from the combustion furnace 124 to the outer cylinder 123 of each pyrolysis device 121 is increased (Step SC3). Thus, thermal load in the pyrolysis device 121 of each of the equipment main bodies 100E and 100C increases.

Subsequently, the control device 109 adjusts the flow rate adjustment valve 103 a to supply the low-temperature heating gas 12 and the waste-heat gas 13 to the inlet 122 a side of the inner cylinder 122 of the pyrolysis device 121 via the mixed gas distribution pipe 105 a (Step SB4). By the low-temperature heating gas 12 and the waste-heat gas 13, the inner cylinder 122 of the pyrolysis device 121 and the pyrolysis gas supply pipe 101 a of the equipment main body 100A are purged of the pyrolysis gas 14. Moreover, the oxygen concentration of the gas inside the inner cylinder 122 and the pyrolysis gas supply pipe 101 a becomes about 1 to 2%, so that the tar is oxidatively decomposed to be reduced in weight. Then, the light gas obtained by the weight reduction is combusted. Hence, attachment of the tar to the wall surface of the inner cylinder 122 and the wall surface of the pyrolysis gas supply pipe 101 a is prevented.

Subsequently, all the pyrolysis coal 3 is discharged from the inner cylinder 122 of the pyrolysis device 121 of the equipment main body 100A (Step SB5), and the supply of the heating gas 11 to the outer cylinder 123 of the pyrolysis device 121 of the equipment main body 100A is stopped (Step SB6). Consequently, thermal load in the pyrolysis device 121 of the equipment main body 100A decreases. Meanwhile, in the equipment main bodies 100B and 100C, the supply of the heating gas 11 to the outer cylinder 123 of the pyrolysis device 121 of each of the equipment main bodies 100E and 100C is brought to the steady state (Step SC4). Thereby, the pyrolysis device 121 of each of the equipment main bodies 100E and 100C maintains the state of the increased thermal load.

Next, in the equipment main body 100A, when a predetermined period of time elapses after the stop of the supply of the heating gas 11 to the outer cylinder 123 of the pyrolysis device 121 of the equipment main body 100A (Step SB7), the pyrolysis gas 14 is no longer in the inner cylinder 122 of the pyrolysis device 121 and the pyrolysis gas supply pipe 101 a of the equipment main body 100A, and therefore no more supply of the low-temperature heating gas 12 and the waste-heat gas 13 is necessary. Thus, the supply of the low-temperature heating gas 12 and the waste-heat gas 13 to the inlet 122 a side of the inner cylinder 122 of the pyrolysis device 121 of the equipment main body 100A is stopped (Step SB8). In this Step SB8, work such as maintenance and inspection is performed on the equipment main body 100A when necessary.

Next, once the work such as maintenance and inspection is finished, to bring the equipment main body 100A back to the steady operation state, first, in the equipment main body 100A, transfer of the dried coal 2 from the drying device 111 into the inner cylinder 122 of the pyrolysis device 121 is started (Step SB9). Thereby, the amount of the dried coal 2 inside the inner cylinder 122 of the pyrolysis device 121 of the equipment main body 100A increases. Thus, the amount of the heating gas 11 supplied from the combustion furnace 124 to the outer cylinder 123 of the pyrolysis device 121 is increased (Step SB10). Thereby, thermal load in the pyrolysis device 121 of the equipment main body 100A increases. Meanwhile, in the equipment main bodies 100E and 100C, the amount of the dried coal 2 transferred to the inner cylinder 122 of the pyrolysis device 121 of each of the equipment main bodies 100E and 100C is decreased (Step SC5). Since this decreases the amount of the dried coal 2 inside the inner cylinder 122 of the pyrolysis device 121 of each of the equipment main bodies 100E and 100C, the amount of the heating gas 11 supplied from the combustion furnace 124 to the outer cylinder 123 of each pyrolysis device 121 is decreased (Step SC6). Consequently, thermal load in the pyrolysis device 121 of each of the equipment main bodies 100E and 100C decreases.

Thereafter, when the amount of the dried coal 2 supplied to the inner cylinder 122 of the pyrolysis device 121 of the equipment main body 100A reaches a predetermined amount and also when the amount of the heating gas 11 supplied to the outer cylinder 123 of the pyrolysis device 121 reaches a predetermined amount, the equipment main body 100A is back in the steady operation state (Step SB11). Meanwhile, when the amount of the dried coal 2 supplied to the inner cylinder 122 of the pyrolysis device 121 of each of the equipment main bodies 100E and 100C reaches a predetermined amount and also when the amount of the heating gas 11 supplied to the outer cylinder 123 of each pyrolysis device 121 reaches a predetermined amount, the equipment main bodies 100E and 100C are also back in the steady operation state (Step SC7).

In a case of shutting down the equipment main body 100B or the equipment main body 100C, operation according to the procedures as described for the equipment main body 100A above can also prevent attachment of tar to the inner wall surfaces of the inner cylinder 122 of the pyrolysis device 121 and the pyrolysis gas supply pipe 101 b or 101 c of the equipment main body 100B or 100C. In other words, by performing the above-described operation sequentially on equipment main bodies to be shut down, tar can be efficiently removed in each equipment main body to be shut down, while suppressing lowering of the operating rate of the entire upgraded coal production equipment.

Hence, in the upgraded coal production equipment of this embodiment, like the upgraded coal production equipment 100 according to the first embodiment described above, to shut down an equipment main body, the low-temperature heating gas 12 and the waste-heat gas 13 are supplied to the inlet 122 a side of the inner cylinder 122 of the pyrolysis device 121 of the equipment main body to be shut down, in order to forcibly discharge the pyrolysis gas 14 inside the inner cylinder 122 of the pyrolysis device 121 and inside the pyrolysis gas supply pipe. This pyrolysis gas 14 is combusted in the combustion furnace 124.

Further, since the oxygen concentration of the low-temperature heating gas 12 and the waste-heat gas 13 is about 2 to 3%, tar can be oxidatively decomposed to become light in weight. The gas thus reduced in weight flows the combustion furnace 124 and is combusted inside the combustion furnace 124. Even if tar is attached to the inner wall surface of the inner cylinder 122 of the pyrolysis device 121 or the inner wall surface of the pyrolysis gas supply pipe, the tar can be removed by the combustion.

Thus, even in shutting down an equipment main body, tar can be efficiently removed without lowering the production volume of the upgraded coal 4. In addition, since tar can be prevented from being attached to the inner wall surfaces of the inner cylinder 122 of the pyrolysis device 121 and the pyrolysis gas supply pipe, maintenance and inspection work can be efficiently performed.

Other Embodiments

Although the upgraded coal production equipment described above has three upgraded coal production equipment main bodies 100A, 100B, and 100C arranged in parallel, the number of the upgraded coal production equipment main bodies is not limited to three, but the upgraded coal production equipment may have two or four or more upgraded coal production equipment main bodies arranged in parallel.

The upgraded coal production equipment described above is configured to stop supply of the low-temperature heating gas 12 and the waste-heat gas 13 to the inner cylinder 122 of the pyrolysis device 121 of the equipment main body 100A based on a period of time elapsed after the stop of the supply of the heating gas 11 to the outer cylinder 123 of the pyrolysis device 121 of the equipment main body 100A. The upgraded coal production equipment can also stop the supply of the low-temperature heating gas and the waste-heat gas to the inner cylinder of the pyrolysis device of the equipment main body to be shut down, based on measurement values obtained by measurement instruments, such as the differential-pressure measurement instruments 107 a, 107 b, of the equipment main body to be shut down.

INDUSTRIAL APPLICABILITY

The upgraded coal production equipment and the method for controlling the same according to the present invention can remove tar efficiently without lowering the production volume of upgraded coal even in shutting down the equipment, and can therefore be utilized significantly beneficially in various industries.

EXPLANATION OF REFERENCE NUMERALS

-   -   1 low-rank coal     -   2 dried coal     -   3 pyrolysis coal     -   4 upgraded coal     -   11 heating gas     -   12 low-temperature heating gas     -   13 waste-heat gas     -   14 pyrolysis gas     -   51, 51 a to 51 c heating gas feed pipe     -   52, 52 a to 52 c exhaust pipe     -   53, 53 a to 53 c heating gas branch pipe     -   54, 54 a to 54 c waste-heat gas feed pipe     -   55 mixed gas feed pipe     -   56 mixed gas supply pipe     -   100 upgraded coal production equipment     -   100A, 100B, 100C upgraded coal production equipment main body     -   101, 101 a to 101 c pyrolysis gas supply pipe     -   102, 102 a to 102 c mixed gas branch pipe     -   103, 103 a to 103 c flow rate adjustment valve (three-way valve)     -   104, 104 a to 104 c mixed gas communication pipe     -   105, 105 a to 105 c mixed gas distribution pipe     -   106 gas temperature measurement instrument     -   107 a, 107 b differential pressure measurement instrument     -   108 inner-cylinder gas temperature measurement instrument     -   109 control device     -   111 drying device     -   121 pyrolysis device     -   122 inner cylinder     -   123 outer cylinder     -   124 combustion furnace     -   125 steam generator     -   126 blower     -   127 exhaust gas treatment device     -   131 cooling device 

1. Upgraded coal production equipment including drying means for drying coal, pyrolysis means for performing pyrolysis on the dried coal, and cooling means for cooling the coal subjected to the pyrolysis, the pyrolysis means being an indirect-heating pyrolysis device having an inner cylinder into which the dried coal is transferred and an outer cylinder which is supplied with a heating gas for heating the inner cylinder, characterized in that the equipment comprises: heating gas generation means for generating the heating gas; pyrolysis gas supply means for supplying the heating gas generation means with a pyrolysis gas generated in the inner cylinder; waste-heat gas generation means for receiving supply of part of the heating gas generated in the heating gas generation means and generating a waste-heat gas by subjecting the heating gas to heat exchange; and mixed gas distribution supply means for distributing and supplying, to the inner cylinder, the waste-heat gas and a low-temperature heating gas generated when the heating gas heats the coal indirectly inside the outer cylinder.
 2. The upgraded coal production equipment according to claim 1, characterized in that the mixed gas distribution supply means is connected to the inner cylinder at an inlet side of the inner cylinder which receives the dried coal.
 3. The upgraded coal production equipment according to claim 2, characterized in that the indirect-heating pyrolysis device includes gas temperature measurement means for measuring a gas temperature, the gas temperature measurement means being provided at an outlet side from which the dried coal is discharged, and the mixed gas distribution supply means includes gas flow rate adjustment means for adjusting a flow rate of the low-temperature heating gas and the waste-heat gas supplied to the inner cylinder, and control means for controlling the gas flow rate adjustment means based on the gas temperature measured by the gas temperature measurement means.
 4. The upgraded coal production equipment according to claim 3, characterized in that the equipment comprises a plurality of equipment main bodies being arranged in parallel and each having the drying means, the indirect-heating pyrolysis device, and the cooling means.
 5. A method for controlling the upgraded coal production equipment according to claim 3, characterized in that the method comprises: stopping supply of the coal to the inner cylinder; supplying the low-temperature heating gas and the waste-heat gas to the inner cylinder through control of the gas flow rate adjustment means by the control means, and meanwhile increasing an amount of fuel supplied to the heating gas generation means; and stopping the supply of the low-temperature heating gas and the waste-heat gas to the inner cylinder through control of the gas flow rate adjustment means by the control means when the gas temperature measured by the gas temperature measurement means falls below a predetermined temperature.
 6. A method for controlling the upgraded coal production equipment according to claim 4, the method comprising: in the equipment main body to be shut down, stopping supply of the coal to the inner cylinder, and meanwhile, in the equipment main body in steady operation, increasing an amount of the coal supplied to the inner cylinder and increasing an amount of the heating gas supplied to the outer cylinder; in the equipment main body to be shut down, starting supply of the low-temperature heating gas and the waste-heat gas to the inner cylinder through control of the gas flow rate adjustment means by the control means; in the equipment main body to be shut down, stopping the supply of the heating gas to the outer cylinder when all the coal is discharged from the inner cylinder, and meanwhile, in the equipment main body in steady operation, bringing the supply of the heating gas to the outer cylinder to a steady state; and in the equipment main body to be shut down, stopping the supply of the low-temperature heating gas and the waste-heat gas to the inner cylinder through control of the gas flow rate adjustment means by the control means when all the pyrolysis gas is discharged from the inner cylinder. 